Roll throttle for air operated hand tool



April 2, 1963 D. n. DOEDEN 3,083,944

ROLL THROTTLE FOR AIR OPERATED HAND TooL Filed March 1'7, 1960 FIG. 1

FIG. 6 35" 48 4a 34 l BY 3 46 l/3| @1am 170%/ www@ 43 ATToRNEYs INVENTOR.

DOUGLAS D. DOEDEN United States Patent O 3,083,944 ROLL THRTTLE FOR AIR @PERATED HAND TOOL Douglas l). Doeden, Hicksville, Ohio, assigner to Doeden Tool Corporation, Hicksville, Ohio, a corporation ot @hic Fiietl Mar. 17, 1960, Ser. No. 15,636 7 @lait-ns. (Cl. 75l-Zo) This invention relates `gener-ally, as indicated, to a roll throttle for `air operated hand tools and more particularly to throttle improvements in air operated hand tools of the type disclosed, for example, in the copending application of Roland E. Doeden, Serial No. 643,092, tiled February 28, 1957, now Patent No. 2,946,315 `and the patent to Roland E. Doeden, No. 2,830,560, both such application and patent being .assigned to the Doeden Tool Corporation, of Hicksville, Ohio.

While the above-mentioned `application and patent disclose `air operated hand tools that have met with wide commercial acceptance, the employment of control valves in which the control element protrudes from the housing creates a safety problem, especially when the tool ernployed has la right angle drive. Moreover, it has been generally diliicult properly to control the acceleration and deceleration of tools of this type employing `conventional control valves. Improper acceleration results in excessive shock loads on the motor and especially on gears if the hand tool is employed with a right angle gear drive. Moreover, there may be severe `shock load when the throttle is shut olf on conventional tools when driving large tools having substantial angular momentum, such as Sanders with large discs. The abrupt shutoff of the throttle causes a reverse torque in the motor and, accordingly, it is easy to see how such shock load can result in the motor and drive when the air supply is abruptly stopped. Moreover, with most conventional throttles, no provision is made to lock the throttle in an on position for continuous operation. Furthermore, if a button or lever protrudes from the housing, such is, of course, subject to damage by improper handling of the tool.

It is accordingly `a principal object of my invention to provide a novel throttle control for an air operated hand tool.

It is a further principal object of my invention to provide a throttle control for an air operated hand tool which will increase the life of the tool ,and `drive used therewith as well as markedly increase the ease of operating such tool.

It is still another object of my invention to provide a throttle control for air operated hand tools which has no protruding buttons or levers which can inadvertently place the tool in operation.

It is a still further object of my invention to provide a throttle control for air operated hand tools 'and the like in which the acceleration and deceleration of the tool can closely be controlled.

It is a yet further object of my invention to .provide an air operated hand tool throttle control which will not fatigue the hand of the user when maintaining the throttle open for any length of time.

It is yet another object of my invention to provide a roll throttle for ian air operated hand tool incorporating a `cam surface to obtain the desired valve adjustments and which will lock in both the full-on and full-off positions.

Other objects and advantages of the present invention ICC will become apparent 'as the following description proceeds.

To the accomplishment of the foregoing yand related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the Ifollowing description and the annexed drawing setting forth in `detail certain illustrative embodiments of the invention, these being indicative, however, of but -a -few of the various ways in ywhich the principle of the invention may be employed.

In said annexed drawing:

FIG. l is a side elevational view of an air operated hand tool employing an angle drive sander 4and including the illustrated embodiment of my throttle control;

FIG. 2 is a fragmentary sectional view on `a somewhat enlarged scale illustrating the details of my throttle control;

FIG. 3 is a transverse sectional view taken substantially on the line 3-3 of FIG. 2;

FIG. 4 is a detail View showing the end of the throttle housing as seen from the right in FIG. 5;

FIG. 5 is a transverse sectional view taken substantially on the line 5-5 of FIG. 4; and

FIG. 6 is a fragmentary sectional View of the valve stem Adetails of FIG. 2 on a substantially enlarged scale.

Referring now to the drawing and more particularly to FIG. l, l have illustrated my throttle control employed on an angle drive, air operated hand tool driving a rotary sander. The cylindrical motor housing 1 is fluted as shown at 2 providing 'a better grip for such housing. On the end of such housing, there is provided the rotatable throttle housing or member 3 in the `form of a sleeve of substantially the same external diameter as the motor housing having a peripherally knurled surface 4 whereby the throttle housing may readily be rotated with respect to the motor housing i1. On the opposite end of the housing 1, I provide a thimble or lock ring 5 which, with right and left h-and internally threaded nut 6, functions to clamp right angle attachment 7 to y the motor assembly within the housing 1. The output spindle of the right angle drive may be adapted as shown at 8 for the use of a sanding pad generally shown at 9. Stich illustrated sander pad is in the form of la rubber disc 16 having .an abrasive disc 11 cemented thereto, as for example, by a pressure sensitive adhesive. lf desired, a clamping nut (not shown) may be employed for this purpose, such being threaded to the output spindle. For ya more detailed disclosure of the mounting of the angle drive 7 on the motor housing of the air operated hand tool, reference may be had to the aforementioned co-pending application of Roland E.. Doeden, Serial No. 643,092.

As seen more clearly in FIG. 2, the motor housing 1 is provided with an axial rearward extension 12 having a central .annular passage 13 therein. The end of this passage is threaded as shown at 14 whereby the flexible air hose may readily be coupled thereto. In this manner the tool can conveniently be sup-plied with a source of air pressure. The throttle housing 3 closely abuts the shoulder 15 on lthe motor housing l formed by the reduced diameter of the `axial rearward extension 12 and is held in place on such extension by a set screw type dog 16 which may be threaded into the throttle housing 3. To improve the appearance of the throttle control and to eliminate sharp corners, the axial extension 12 of the motor housing l is reduced in diameter at the end thereof, as shown at 17, and the throttle housing 3 is curved to provide a rounded end 18 for the tool.

The extension 12 is provided with a hardened sleeve 19 to provide Aa bearing surface for the interior of the throttle housing 3 whereby it may rotate readily on such extension without causing excessive wear. Moreover, the use of the hardened sleeve 19 which may, for example, be steel mounted on the housing permits the use of an aluminum housing which is, of course, lighter and can be anodized to match other tools of this type. The sleeve 19 is provided wtih an arcuate slot 20 closely corresponding to a similar arcuate groove 21 in the extension 12. In this manner the throttle housing 3 may readily be rotated about the axis of the extension within the limits of such slot. Thus the dog or set screw 16 will not preclude the rotation of the throttle housing but merely the axial withdrawal or removal of the housing 3 from the motor housing 1. The sleeve 19 is also provided with a small aperture 22 (FIG. 3) aligned with recess 23 in extension 12 having therein a spring 24 actively pressing on ball detent 25. Such ball detent cooperates with semi-circular grooves 26 and 27 spaced 90 apart on the interior of the throttle housing 3. (Note FIGS. 4 and 5.)

The passageway 13 leads through a reduced portion 30 into a vertically extending transverse passageway 31 in he extension 12 of the motor housing 1. The bottom of this passageway is closed by la plug 32 threaded therewithin, such plug clamping a gasket or ring 33 about such opening to form an effective air seal for the bottom of such vertically extending passageway. Closing the top of the vertically extending passageway 31 is a bushing 34 having a vertically extending passageway or slideway 35 therethrough. A transverse passageway 36 extends through both walls of the bushing 34 providing air communication between the interior vertically extending passageway 35 and annular passageway 37 recessed within the exterior of the bushing 34. The annular passageway 37 communicates directly with apertures 38 and 39 in the rear wall 40 of the motor housing -1 (FIG. 3).

Positioned within the vertically extending passageway 35 is a valve stem 41 having a button 42 on the top thereof and an enlarged portion 43 on the bottom havin-g an annular O-ring retaining groove 44 therein. The valve stem is maintained in its uppermost or closed position by the action of compression spring 45 seated within the plug 32 and bearing against the bottom enlarged portion 43 of the stem 41. In the closed position of the valve, the O-ring 46 within the groove 44 will bear against the bottom edge of the passageway 35 within the bushing 34 effectively closing the valve to the passage of air therethrough. It can now be seen that a downward pressure on the button 42 of the valve stem 41 will move the valve stem downwardly against the pressure of the spring 45 to move the O-ring away from the bottom opening in the bushing 34 effectively to open the valve to permit air to flow therethrough. As seen more clearly in FIG. 6, the shank portion 47 of the stem 41, which closely fits within the vertically extending passageway 35 of the bushing 34, is tapered slightly as shown at 48 such that downward movement of the stem 41 will provide a gradual increase in the volume of air flowing through such valve. This taper, in cooperation with my special control for the movement of the valve stem, permits better control of the acceleration and deceleration of the tool.

Air entering the passageways 38 and 39 through the valve mechanism just described serves to drive the motor 50 by rotating the rotor 51, one end of which is journalled as shown at 52 in end plate 53. The details of this motor are quite conventional, reference being had to either the aforementioned copending application or issued patent to Roland E. Doeden.

In order to provide an effective control for my valve construction, l provide an interior cam surface 54 on my rotatable throttle housing 3. The profile of this cam may more clearly be seen in FIG. 4 and it is apparent that movement of the throttle housing 3 through a 90 arc in a clockwise direction as shown in FIG. 4 will move the point of contact of the button 42 with the cam sur. face 54 from the full-Gif point 55 to the full-on point 56.

It is noted that the full-on point S6 as well as the full-off point 55 have diametrically opposed thereto respective grooves 26 and 27 to engage the ball detent 25 whereby my roll throttle valve may be locked in either the full-on or full-off position. rthis, of course, relieves the necessity of the operator continually gripping the valve for any length of time which can be very fatiguing.

As seen in FiG. 5, the housing or sleeve 3 is provided with a threaded opening 57 readily to accommodate the dog 16 to lock the housing 3 `and extension 12 against axial movement. Moreover, the shape of the housing 3 is such that it may readily be gripped by the hand of the operator which is not employed to grip the motor housing 1, lthe knurled surface 4 readily assisting in the easy turning of the housing 3 with respect to the motor housing 1. Thus my hand tool has a cylindrical body or housing and may be controlled by rotating one portion of the body with respect to another.

lt can now be seen that l have provided a throttle control for air operated hand tools which will (l) increase the safety of such tools in that there are no protruding parts which may inadvertently be contacted to actuate the motor; (2) increase the life of the tool and the associated drive train in that the acceleration and deceleration of the tool can readily be controlled; (3) increase the ease of operation in that the throttle housing 3 need only be twisted with respect to the motor housing 1 and it can be locked in the on position thus relieving the fatigue associated with the continual hand pressure required to operate conventional valves; and (4) preclude the inadvertent damage to projecting parts such as levers and buttons which may result from the use of more conventional valves. Moreover, the clean tubular configuration of my tool contributes markedly to the design appearance er1- hancing considerably the commercial acceptance thereof.

Other modes of applying the principles of the invention may be employed, change being made as regards the details described, provided the features stated lin any of the following claims or the equivalent of such be employed. l

I, therefore, particularly point out and distinctly claim as my invention:

1. A throttle control for air operated hand tools and the like having an elongated motor housing adapted for holding in the hand, an axial extension on said housing having an air passageway therein adapted to be connected to a source of air under pressure, a valve mechanism in such passageway controlling the ow of air to said motor housing, Ka tubular member surrounding said extension and adapted to be rotated with respect to said housing, and means responsive to the rotation of said member about said extension to move said valve mechanism thereby to control the ow of air to said motor housing, said valve mechanism including a valve stem mounted for movement transversely of such passageway; said means comprising a cam surface on the interior of said member engaging -said valve stem effective upon rotation of said member through a prescribed arc to cause movement of said valve stem to an open position, spring means resiliently to hold said valve stem against said cam surface, and ylock means for said valve mechanism to hold said valve in open position.

2. A throttle control as set forth in claim 1 wherein said valve stern serves Ito close an opening in a bushing disposed normal to such passageway, said stem including a tapered shank portion adjacent such opening to provide a gradual increase in ow as said valve stem is moved axially with respect to said bushing.

3. A throttle control as set forth in claim 2 wherein the external diameter of said motor housing is substantially the same as the external diameter of said member.

4. A throttle control as set forth in claim 3 wherein 'the external isurface of both said motor housing and member is roughened to facilitate relative manual rotation thereof.

5. A throttle control as set forth in claim 1 wherein said lock means comprises a groove on the interior of said member disposed diametrically .opposite the full-open position on said cam surface, said groove cooperating with a `spring pressed ball detent mounted in said extension.

6. A throttle control for air operated hand tools and the like comprising an yelongated motor housing for such hand tool adapted or holding in the hand, an extension on said housing axially thereof having an air passage- Way therein adapted to be connected to a source of air under pressure, a valve mechanism in such passageway controlling the flow of a-ir to said motor housing, a tubular member `surnounding .said extension and adapted -to be rotated with respect to said housing, means responsive to the rotation of :said member about said extension to move said valve mechanism thereby to control the flow of air to said motor housing, and a dog removably secured to `said member and projecting inwardly into an arcuate slot in lsaid extension, such slot being in a plane normal to the axis of said extension and permitting but limiting relative rotation of said member .and motor housing and precluding axial movement and removal of said member from 4said housing extension.

7. An air operated hand tool comprising -an elongated motor housing adapted to be held in the hand, -an axial air inlet for said motor housing, a valve member extending transversely into 'said inlet, means to rotate one por-.tion of said housing with respect to another directly to control the position of said valve member, said housing being made of aluminum and said one portion rotating on a hardened sleeve mounted on an extension of said 'other portion and arcuate lslot means in said sleeve and lsaid extension cooperating with la removable dog in said one portion of said housing permitting but limiting such rotation.

References Cited in the file of this patent UNITED STATES PATENTS 674,971 Kirnman May 28, 19011 841,322 Hoxie Ian. 15, 1907 1,006,514 Waugh Oct. 24, 1911 1,150,641 Smith Aug. 17, 1915 2,155,082 Decker Apr. 18, 1939 2,570,009 Schmid Oct. 2, 1951 2,657,709 Gillerstrom et al. Nov. 3, 1953 2,715,512 Miller et al. Aug. 16, 1955 2,830,560 Doeden Apr. 15, 1958 2,877,820 Ristow Mar. 17, 1959 FOREIGN PATENTS 1,142,160 France Sept. 13, 1957 

1. A THROTTLE CONTROL FOR AIR OPERATED HAND TOOLS AND THE LIKE HAVING AN ELONGATED MOTOR HOUSING ADAPTED FOR HOLDING IN THE HAND, AN AXIAL EXTENSION ON SAID HOUSING HAVING AN AIR PASSAGEWAY THEREIN ADAPTED TO BE CONNECTED TO A SOURCE OF AIR UNDER PRESSURE, A VALVE MECHANISM IN SUCH PASSAGEWAY CONTROLLING THE FLOW OF AIR TO SAID MOTOR HOUSING, A TUBULAR MEMBER SURROUNDING SAID EXTENSION AND ADAPTED TO BE ROTATED WITH RESPECT TO SAID HOUSING, AND MEANS RESPONSIVE TO THE ROTATION OF SAID MEMBER ABOUT SAID EXTENSION TO MOVE SAID VALVE MECHANISM THEREBY TO CONTROL THE FLOW OF AIR TO SAID MOTOR HOUSING, SAID VALVE MECHANISM INCLUDING A VALVE STEM MOUNTED FOR MOVEMENT TRANSVERSELY OF SUCH PASSAGEWAY; SAID MEANS COMPRISING A CAM SURFACE ON THE INTERIOR OF SAID MEMBER ENGAGING SAID VALVE STEM EFFECTIVE UPON ROTATION OF SAID MEMBER THROUGH A PRESCRIBED ARC TO CAUSE MOVEMENT OF SAID VALVE STEM TO AN OPEN POSITION, SPRING MEANS RESILIENTLY TO HOLD SAID VALVE STEM AGAINST SAID CAM SURFACE, AND LOCK MEANS FOR SAID VALVE MECHANISM TO HOLD SAID VALVE IN OPEN POSITION. 